How long are you shaking my hand?

Suppose you were a fictional female character in my story: you walk up and introduce yourself with your hand extended. You are wearing a tucked-in plaid shirt with the sleeves rolled up and belted blue jeans. I give you my hand and you shake firmly with a mischevious look on your face. I wait a few seconds then try to let go but you keep a firm grip and continue shaking. How long does the handshake last in minutes and seconds and what color is your shirt?